Apparatus for the rolling or twisting of yarn or ribbon-like structures about their longitudinal axis

ABSTRACT

Textile structures, such as yarns or ribbons, are twisted or rolled by moving the rubbing surfaces of two rubbing rollers relative to one another transversely of the longitudinal direction of the structure passing therebetween, at least one of said rubbing rollers comprising a plurality of peripheral segments or sections which are successively engaged with the other rubbing roller and while so engaged are moved axially, i.e., transversely, of the feeding direction of the structure and are returned to their initial positions during the periods of non-engagement with the other rubbing roller.

[ 1 Aug. 29, 1972 United States Patent Rasmussen et al.

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2,601,394 6/1952 Hansen...................57/77.4X 2,991,614 7/1961Ubbelohde .............57/77.4 X

[72] Inventors: Ole-Bendt Rasmusen, Topstykket,

3460 Birkerod; willy Bach M i 3,328,950 7/1967 Scragg et al..............57/77.42 alby fi z t gi ggg y Primary Examiner-JohnPetrakes 8 7 2750 Banemp, f I V Attorney-W1ll1am J. Daniel ABSTRACTTextile structures, such as yarns or ribbons,

are twisted or rolled by moving the rubbing surfaces of two rubbingrollers relative to one another transversetudinal direction of thestructure passing of said rubbing rollers comprising a plurality ofperipheral segments or sections which are successively engaged with theother rubbing roller and while so engaged are moved axially, i.e., ofthe feeding direction of the structure d to their initial positionsduring the engagement with the other rubbing e n O k m m 9 mm H VH1. mmw 3 C re 6 S mm w om add 0 Wm umm... 999 6 8 MMK N mum s17 mun mug m: sm2 m W: H "u" 27 m mm 7 flh m m: m kkk m 9, m m w 5 1 n i .mnmn W m 0.5m 5 k 2 w ""7 m 1 u :5 D. 9 n M, P69 uh I A 99 "0c 2 111 um 0 0 N m 2211.2... m m mmi n 1 m w w smut 1 1]] 2 l 0 2 00 2 2 3 555 ['IIL'IL 9Claims, 8 Drawing Figures BACKGROUND OF THE INVENTION Strand rollingprocesses are in general known for various purposes within the textileindustry and relates industries. It is i.e. known to perform such arolling in combination with the spinning of staple yarn, the rollingbeing performed on the raw yarn in order to increase the coherencebetween the individual fibers and to make the cross section of the yarnmore circular. The rolling is also employed in the yarn texturizing,where it is known to utilize such a rolling for producing a strong twistwhich is combined with a heat treatment or other fixing process capableof giving the material an inclination to revert to the twisted statewhen thereafter relaxed. Finally, it is known to use such a rollingprocess in the production of split or fibrillated fibers whereinorientated foil strips are split or fibrillated, usually under arelatively heavy pressure, into fibers, which still cohere in the formof a yarn. The orientation required for this purpose may e.g. beproduced by a strong molecular orientation (although this as is wellknown does not always produce sufficient splittability), or it may beproduced by a strong stretching of a mixed structure in molten state.

A rolling of the type under consideration has been produced by means oftwo rubber rollers, which are separately reciprocated along their axes,while at the same time being rotating to feed the strand forwardlongitudinally, or by similar means. However, the effect of these knownrolling means is relatively non-uniform, which is of particulardisadvantage in the production of split fibers where variation of thefineness of the fibers will result, and where the process isparticularly critical owing to the required relatively high rollerpressures. These drawbacks may to some extent be remedied either byfeeding the yarn very slowly in relation to the time of reciprocation orby using a very large number of such rolling stations after one another.This, however, will tend to make the process relatively uneconomical.

It is an object of the invention to remedy these drawbacks and in such away as to permit a particularly high speed of production.

SUMMARY OF THE INVENTION According to the invention, there is used atleast one rubbing body comprising a plurality of rubbing elements whichare successively engaged with another rubbing body and, while being soengaged, are moved transversely of the feeding direction of the textilestructure said rubbing elements being restored to their initial positionduring the periods of non-engagement with the other rubbing body.

Thus, according to the invention the rolling or twisting of the textileis performed structure in a substantially continuous process withsubstantially constant rolling in the same direction, whereby therolling effect will be uniform and the treatment can be carried out in apractical way and at a high feeding speed.

The minimum number of rubbing elements is two, but it is preferred touse a greater number, e.g., 8l5, because it then becomes possible to usehigher speeds without substantial complication of the construction ofthe required apparatus.

The other rubbing body located on the opposite side of the structure maye.g., be a rotating roller having a rubbing surface or, in a very simpleembodiment, a stationary body having a rubbing surface. However, toobtain the highest possible speed of rotation in the rolling operationthe other rubbing body preferably likewise comprises a plurality ofrubbing elements, which are successively engaged with the first rubbingbody, the rubbing elements at any time engaged with each other beingmoved in opposite directions.

In a preferred embodiment of the invention at least, one and bothpreferably rubbing bodies consists of a roller having a plurality ofseparately axially displaceable peripheral segments or sections, eachextending over part of the circumference of the roller.

The rubbing surfaces may be sand blasted or finely fluted metal surfacesor rubber coatings which are attached directly to the rubbing elements.However, in one manner of carrying out the process, the transversemovement of the rubbing elements is applied to the structure through themedium of an endless bands. In this way the lifetime of the rubbingsurfaces is increased. To avoid transverse slipping between the bandsand the rubbing elements, the side of the bands, which is in directcontact with the elements, may be longitudinally fluted and the surfacesof the rubbing elements may be similarly fluted for engagement with thefluting pattern of the band.

For splitting and texturizing purposes, the rubbing surfaces areadvantageously moved at relatively dif ferent speeds in the structurefeeding direction. In this manner, a displacement action is imparted tothe structure simultaneously with the rolling, which displace mentaction all the time affects the surfaces of the structure in oppositedirections, an influence constantly taking place on different parts ofthe surfaces of the structures.

An apparatus for carrying out the invention may comprise means forestablishing a substantially linear zone between two rubbing bodies withthe structure gripped therebetween, and means for moving the rubbingelements provided on at least one of the bodies relative to one anothertransversely of the structure, while the same is being fed forward,according to the invention at least one of said rubbing bodies comprisesa plurality of rubbing elements, together with means for successivelyengaging said rubbing elements with the other rubbing body, and meansfor displacing said rubbing elements transversely of the feedingdirection of the structure during the period of their engagement withthe opposed rubbing body and for restoring said rubbing elements totheir initial position during the periods of their non-engagement withthe opposed rubbing body.

Advantageously at least one of said rubbing bodies consists of a rollercomprising a plurality of separately axially displaceable rollersegments or sections, each extending over part of the periphery orcircumference of the roller.

According to another preferred embodiment of the invention, said otherrubbing body also comprises a plurality of rubbing elements, and meansare included for successively engaging said rubbing elements with saidfirst rubbing body, and means for moving the rubbing elements while inengagement with each other in opposite directions.

In the case where at least one rubbing body is in the form of asectional roller, the rubbing elements may be carried by a core portionin such a manner as to be displaceable relative to this core portion inthe longitudinal direction of the roller. The roller is also providedwith means for reciprocating the sections synchroneously with therotation of the roller. These means may advantageously consist of one ormore stationary guiding tracks or guiding curves and one or morecorresponding cams or guide members on each of the said sections.

The apparatus of the invention may also be constructed in other ways.For example the rubbing elements may be mounted on a set of endlesscarriers, which are so arranged that the rubbing elements are movedtransversely of the feeding direction of the structure, which in thiscase may be the direction of the carriers.

The invention has utility in connection with the molecular orientationof thermoplastic polymers in the form of one or more ribbon-likestructures or strips, the structures being heated and stretched within apredetermined zone up to several times their original length.

A stretching for the molecular orientation of thermoplastic polymers isusually carried out by means of two sets of rollers, one of which beinglocated at one end of the stretching zone and the other being located atthe other end of the zone, the first mentioned set of rollers beingrotated at a lower circumferential rate of speed than the last mentionedset of rollers.

It is customary to localize the position of the stretching zoneaccurately by means of a friction body (smooth metal surfaces willnormally provide sufficient friction for this purpose), and moreover theinput rollers may be replaced by friction bodies, the speed of thematerial across these bodies being then controlled by adjustment of thefrictional effect.

To facilitate the stretching, the material is, as mentioned above,frequently heated either by means of a hot-air oven in the stretchingzone or by heating the input rollers or the intermediate friction body.

The apparatus of the invention is helpful in reducing risk of ruptureduring the stretching operation just described.

Thus the structure are subjected or structures in a continuoussuccession of operations, to a twisting before or while being stretchedin heated condition, the twist thereby inserted being thereafterentirely or partly removed. The twisting is preferably carried out byrolling the structures about their longitudinal axes in the mannerpreviously described, but other twisting methods, known per se, mayalternatively be used.

It has been found that by the combined twisting and stretching aconsiderable reduction of the frequency of ruptures at a certainstretching ratio is obtained particularly where the material hasdistinct defective spots, e.g., resulting from occluded air blisters, aninhomogenous distribution of relatively high molecular and relativelylow molecular components, a nonuniform thickness or notches at the edgeof the ribbonlike structure or structures. By the twisting the structureassume a more compact character, the individual portions of a crosssection through the structure or structures being held together byfrictional forces,

takes considerably longer time to heat the material in a twisted state.

For practical reasons, it is preferable to produce the twist by rollingthe structures between a pair of rubbing bodies located at the outputend of the stretching zone. Usually a plurality of ribbon-likestructures will be stretched simultaneously, and eventually these willbe coiled in the form of individual packages. It is not necessary toprovide a separate twisting member for each structure, but a pluralityof structures may according to the invention preferably be twisted bymeans of the same pair of rubbing bodies in different areas of theirrubbing surfaces.

For carrying out the combined twisting and stretching operation theapparatus may comprise means for subjecting one or more ribbon-likestructures to localized heating and means for subjecting such structuresto a stretching of several times their original length plus means forsubjecting such structures continuously to twisting before or while theyare being stretched in a heated state and for thereafter entirely orpartly removing this twist.

When treating relatively wide foil strips, e.g., of a width of 3-30 cm,the danger of rupture may be further reduced by arranging thelongitudinal axes of the input or heating rollers, and the auxiliary orstretching rollers respectively at an angle to each other. Hereby thetwisting will take place sooner after the ribbon-like structures haveleft the last one of the sets of input rollers, whereby a possible notchor notch formation will be blocked before a rupture ensues. Likewise theresulting twisting of the structures will be more uniform. It has alsobeen found that at a given stretching ratio the angle between the axesof the rollers should preferably have a value such that its cosine isapproximately equal to or smaller than the square route of thestretching ratio, defined as the ratios between the speeds of travel atthe input and output ends, respectively, of the stretching zone byselecting the angle such as to fulfil the condition, the danger ofrupture at a given stretching ratio may be very considerably reduced.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows diagrammatically, in aperspective view, a set of rollers for use in carrying out the processaccording to the invention, the reciprocating means for the peripheralsegments being omitted to simplify the illustration,

FIG. 2 shows the reciprocating means for a roller of the kindillustrated in FIG. 1, as viewed in front eleva tion with certain partsin section,

FIG. 3 is a cross section taken along the line II in FIG. 2,

FIG. 4 is diagrammatic perspective view of a processing apparatus usingthe rubbing means of the invention for false twisting and, if desired,simultaneously splitting,-

FIG. 5 is an apparatus similar to FIG. 4 for use in the splitting ofribbon-like structures in four stages,

FIG. 6 illustrates a stretching operation in which the twisting isproduced by means of a different kind of sectional roller cooperatingwith another roller,

ment for the stretching ofribbon-like structures.

DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIGS. 1, 2 and 3, 1 is aroller core, which is rotated by drive means not shown, and 2, 3, 4 and5 are peripheral segments or sections constituting the outer rollercircumference. The core 1 and the sections 2, 3, 4 and 5 are soconstructed that the sections are forced to rotate with the core, butare free to reciprocate in the longitudinal direction of the roller. Theillustration is greatly simplified and in practice the sliding movementshould preferably be aided through bearings, which can, e.g., be rows ofrollers. The sections are held together by means of collars, one ofwhich, is shown at 6 in FIGS. 2 and 3. As another possibility thesections and the core could be assembled by means of dovetailconnections or the like. FIGS. 2 and 3 also illustrate the provision ofguiding pins or cam followers 7 on each section and a correspondingguiding groove or cam 8 in the ring 6. This construction too is shown insimplified form and in practice the connections should be established bymeans of bearings. For example each pin 7 may be in the form of a ballor roller bearing. Each section is provided with a rubber coating 9.

In FIG. I, the directions of rotation of the two rollers and thelongitudinal directions of movement of the sections 2 and 4 of eachroller are indicated by arrows. The sections 3 and 5 are stationary inthe moment they occupy the extreme opposite end positions. When therollers have made one fourth of a revolution, the section 2 of the upperroller has been displaced by smooth sliding movement to the positionassumed in the drawing by the section 5. Thus, each section is caused toperform a reciprocating movement, which is synchronized with therotation of the roller. If relatively few sections are used, such asillustrated in the drawing and on principle it is possible to use as fewas two sections the guiding groove 8 should have a substantiallyconstant pitch over a relatively long distance over the region in whichit guides the movement in the clamping zone. The guiding groove shouldhave a configuration such that the roller sections are moved at aconstant sliding speed at least from the moment when the leading edge ofa section reaches the clamping zone to the time the trailingedge of thesame section leaves the clamping zone, i.e., during one fourth'of arevolution when four sections are used as illustrated. If, on the otherhand, 10 or more sections are used, it is usually permissible to let thespeed change gradually.

In the apparatus illustrated in FIG. 4, a group of yarns or strips ofplastic film (for clarity film strips are shown) is fed through a set ofordinary rubber rollers 11 and then through a set of sectional rollers12 performing a rolling by successive influences resulting from rubbingelements, each carrying out a predetermined cycle. Instead of a set ofsectional rollers, it is possible to use, e.g., one sectional rollerco-operating with an ordinary roller. It is also possible to use acombination of an ordinary roller and an array of sections, which areadvanced in a closed path by means of endless chains or belts and at thesame time carry out transverse movements analogous with those of theroller sections described above.

When the yarns or strips 10 are introduced in nontwisted state, therolling will cause them to be twisted when leaving the rollers lll. Thetwisted yarns or strips are denoted by 113. This twisted state is fixedthermally, the material being heated in an oven 14 and subsequentlycooled by means of a blower 15 before entering the set of rollers 12.After the rolling the material is passed on for coiling or spooling (notshown).

The twist inserted at 13 will be removed at 16 and the effect on thematerial of the set of rollers 12 is a so called false twisting so thatthe material when relaxed will tend to return to the twisted state inwhich it was heat-set. If the material consists of strongly orientatedstrips, splitting or fibrillation may take place at the same time andwill be effected to a lesser extent in the zone where the strips aretwisted, i.e., when they leave the rollers 11, and to a greater extentin the zone where they are subjected to rolling by the rollers 12.

Splitting may, however, also be effected without maintaining any falsetwist in the final product, the heat setting or other fiber fixationtreatments illustrated being then omitted. When the present improvementis also to be used for splitting, it is advantageous to repeat therolling several times by means of several stations of the same kindarranged in immediate succession. This is illustrated in FIG. 5. In thesplitting system illustrated in FIG. 5, ribbon-like strips 17 are firstsplit by pure rolling about their longitudinal axes without anydisplacement along the longitudinal axes taking place at the same time.This has been found to be preferably for the starting of the splitting.This treatment takes place by means of a set of rollers 11% constructedwith displaceable sections such as explained above with reference toFIGS. ll, 2 and 3. A series of subsequent sets of rollers 19, 2t) and 21is also constructed with displaceable sections, but during the passagethrough these a combined rolling about the longitudinal axes of thestructures and a displacement along these axes takes place.

To determine the operating conditions when the structures are to besubjected to a pure rolling about their longitudinal axes, and when theyare at the same time to be subjected to displacement along thelongitudinal axes, respectively, the resultant (i.e., vector sum) of thecircumferential speed of rotation and the speed of displacement shouldbe considered for each of the two rubbing surfaces engaging one another.If this resultant is numerically equal (but oppositely directed) for thetwo rubbing surfaces, the structures are subjected to a pure rollingabout the longitudinal axes. If on the other hand the two resultantshave opposite numerical values (and different directions), adisplacement from the longitudinal axes of the yarns takes place at thesame time. It can be observed that it is possible without substantialdrawbacks to select the speed of rotation and displacement of the rollersections in such a manner that the feeding direction of the structuresvaries considerably from a direction perpendicular to the axis of therollers.

Immediately before moving into the'set of rollers 19, the structurestravel through eyes of a reciprocating rod 22 and are thereby introducedinto the clamping zone in a zig-zag pattern, which in this stage usuallypromotes splitting. After splitting in the set of rollers 19, therefollow two ordinary sets of rollers 23 and 24, which subject thestructures to a stretching in order to remove kinks and the like thatmay be formed when the structures are subjected to displacement fromtheir longitudinal axes. The same function is performed by twoadditional sets of rollers 25 and 26, which are arranged after the setof rollers 20, as well as two further sets of rollers 27 and 28, whichare arranged after the set of rollers 21. Moreover, an oven 29 isprovided immediately before the set of rollers 21 and serves to softenthe material immediately before it reaches the last splitting station.The heating in this oven and the cooling, which is effected by means ofa blower 30 and takes place after the splitting station and while thesplit fiber yarns are held in a relatively slack state, serves to fixthe ruffled state, into which the fibers are brought by the splittingaction when they are subjected to displacement from the longitudinalaxes of the structures. Eventually the yarns are spooled.

In the arrangement illustrated in FIG. 7, a plurality of ribbon-likestructures or strips 31 to be orientated are moved in flat non-twistedstate through a heated pair of rollers 32 (the heating means not beingshown) and thereafter to modified rubbing station. Here, pairs ofsegmented rubbing rollers are used as before but instead of theserollers directly contacting the textile structures to be treated, anendless rubber belt 33 is interposed between each roller and thestructure. In this way, the frictional effect is transmitted through therubber belt which therefore receives the resultant wear. In FIG. 7, theset of rubbing rollers have been omitted to better reveal the beltarrangement but the position of the roller set is indicateddiagrammatically by the dotdash line 34. It will be understood that oneroller of the set will be situated above the upper of the belts 33 inpressing contact therewith and the other below the lower of these belts.The sections of the rollers contacted by the belts are reciprocated at arate consistent with the angle made by the paths of travel of the beltswith respect to the direction of travel of the structures. Preferablythe rubbing rollers used here are of the type shown in detail in FIG. 6hereinafter described. A lubricant may be applied between these clampingmeans and the rubber belts if desired.

The two rubber belts are moved at an angle to each other and therebycause the strips clamped therebetween to be rolled. At the same time thestrips are pulled forward by the rubber belts at a speed equal to thecomponent of speed of the rubber belts in the longitudinal direction ofthe machine. The pair of rollers 32 rotate at a lower circumferentialspeed, the ratio between the said component of speed and thecircumferential speed being substantially equal to the desiredstretching ratio. The strips are thereby simultaneously stretched andtwisted. Both stretching and twisting take place predominantly in thezone adjacent the rollers 32 immediately after the strips have leftthese rollers. A set of rollers 35 rotates at a circumferential speedcorresponding to the said component of the movement of the rubber beltsand thereby reinforce the stretching effect they impart. If theserollers were not provided, it would be necessary to clamp the rubberbelts particularly tightly against one another, which would beunpractical. The twisting produced by the rubber belts will be at anyrate substantially removed when the strips leave the clamping zonebetween the rubber bands. In addition to the heating of the rollers 32 ahot air oven may be arranged between these rollers and the clamping zoneof the rubber belts. The stretching zone and the twisting zone maythereby be extended, whereby it becomes possible to use higher feedingspeeds.

In FIGS. 6, the numbers 31, 32 and 35 have the same significance as inFIG. 7. In FIG. 6, however, the rubber belts have been omitted leavingonly the set of rollers 40,41. The roller 40 is shown in dotted linesand is located between the strips 31 and the observer and may be anordinary roller. The roller 41 on the other side of the strips is aperipherally segmented or sectional roller of the same kind as thatshown in FIGS. 1, 2 and 3. The roller 40 however, consists of arelatively great number of segments or sections, which is usuallyadvantageous. In the arrangement of FIG. 6, the roller set 40,41 isshown disposed at an oblique angle to the direction of travel of thestructures instead of at right angles thereto as in FIG. 7 as indicatedby the center line. Line 42 also indicates the projection of thecomposite movement performed by any particular point of any particularsection. The guiding means which displace the sections longitudinally ofthe roller are not shown. When the pitch of the path described by eachpoint of a section in the clamping zone is to be 20:, it is usuallyadvantageous to arrange the rollers 40 and 41 at an angle a to therollers 32 and 35 moreover, the composite speed of the frictionalsurface of the sections in the clamping zone should be equal to thecircumferential speed of the roller 40. Since the feeding directionbecomes the bisecting line of the angle between the movements of the tworoller surfaces, the strips will on principle travel linearly throughthe stretching apparatus. To prevent them from drifting longitudinallyof the rollers, it is, however, advantageous in practice to control theintroduction of the strips into the clamping zones by means of a comb43.

To give the rollers a sufficient frictional surface, they may be sandblasted or rubber coated, but it is also possible to transfer thetransverse movements from these rollers to the strips through endlessrubber belts as mentioned in connection FIG. 7. The rubber belts and theroller surfaces may then be in engagement with each other by means of apattern of flutes or grooves preventing transverse slipping.

The system illustrated in FIG. 8 serves for the stretching of widestrips in such a manner as to reduce the risk of rupture of the strips,which result is obtained by arranging the longitudinal axis of the mainpreheating roller set and the drawing rollers at an angle to each other.Ribbon-like foil strips 51 pass through a set of preheating rollers 52and a set of main preheating rollers 53, whereafter they are twisted ina set of rollers 54, one roller of which consists of two or more axiallyreciprocable roller sections each extending over part of the peripheryof the roller, while the other is a roller performing a pure rotationalmovement. After leaving these twisting rollers, the strips, which arenow entirely or partly twisted, travel through a set of auxiliary orstretching rollers 55, the circumferential speed of which is equal tothe sum of the components in the direction of travel of thecircumferential and axial speeds of the sections of the first mentionedroller 54in the nip zone and also equal to the component in thedirection of travel of the circumferential speed of the other roller 54.As illustrated in the drawing, the twisting of the individual stripswill start immediately after these have left the pair of rollers 53.

We claim:

1. An apparatus for twisting or rolling an advancing textile strandgenerally about its axis which comprises a pair of opposed rollersdefining a nip through which said textile strand passes, at least one ofsaid rollers having its periphery surface constituted of a plurality ofperipheral segments, each mounted for individual movement parallel tothe roller axis and for bodily rotational movement with the remainder ofthe roller, driving means for rotating said roller pair, reciprocatingmeans for imparting axial movement to said peripheral segments as theysuccessively contact said strand and in time relation to the linearspeed of travel of the segment surfaces contacting said strand, andmeans for advancing at least one textile strand to and for withdrawingsaid strand from said pair of opposed rollers along a generallyrectilinear path, said roller pair having the locus of the nip thereofextending across said path.

2. The apparatus of claim 1 wherein both of said opposed rollers havetheir peripheral surfaces constituted of said peripheral segments andsaid reciprocating means reciprocates the segments of both said rollers.

3. The apparatus of claim 2 wherein said reciprocating means moves thesegments of the respective rollers in opposite axial directions atsubstantially equal speeds.

4. The apparatus of claim 2 wherein said reciprocating means moves thesegments of the respective rollers in opposite axial directions atunequal speeds whereby said strand is both twisted and laterallydisplaced.

5. The apparatus of claim 1 wherein said pair of opposed rollers isarranged with their axes extending at an oblique angle to the path ofadvance of the strand.

6. The apparatus of claim 5 wherein each surface of a segment while incontact with said strand is moved axially at a pitch substantially twicesaid oblique angle.

7. The apparatus of claim 1 wherein said segmented roller includes acenter core adapted to be rotatively driven by said driving means, saidcore carrying a plurality of axially extending tracks, each in matingengagement with one of said peripheral segments, permitting individualaxial reciprocation of said segments coincidental with bodily rotationthereof.

8. The apparatus of claim 1 wherein each of said peripheral segments hasa cam follower fixedly associated therewith and said reciprocatingmeanscomprises a cam track engaging said cam followers.

9. An apparatus for twisting or rolling an advancing textile strandgenerally about its axis which comprises a plurality of elongatedelements each having a surface region for frictionally contacting thestrand and arranged generally transversely to the direction of advanceof the strand, said elements being mounted for individual movement toand fro along their longitudinal es for bodil veme t at an an le to sailong itudi ri a i axes in a dy dli cal paili, an oppo ed strancontacting surface maintained in closely spaced relation to one locus onthe path of bodily movement of said elements and cooperating with atleast one element at said locus to tightly engage the strandtherebetween, means for driving said elements along said cyclical path,means for moving each such element passing through said locus in a givenlongitudinal direction in timed relation to the bodily movement of theelement through said cyclical path and subsequently along said cyclicalpath moving said elements in the opposite longitudinal direction, andmeans for advancing at least one textile strand to and withdrawing thestrand from said locus along a generally rectilinear path, said elementat said locus having its longitudinal axis extending generally acrosssaid strand path.

1. An apparatus for twisting or rolling an advancing textile strandgenerally about its axis which comprises a pair of opposed rollersdefining a nip through which said textile strand passes, at least one ofsaid rollers having its periphery surface constituted of a plurality ofperipheral segments, each mounted for individual movement parallel tothe roller axis and for bodily rotational movement with the remainder ofthe roller, driving means for rotating said roller pair, reciprocatingmeans for imparting axial movement to said peripheral segments as theysuccessively contact said strand and in time relation to the linearspeed of travel of the segment surfaces contacting said strand, andmeans for advancing at least one textile strand to and for withdrawingsaid strand from said pair of opposed rollers along a generallyrectilinear path, said roller pair having the locus of the nip thereofextending across said path.
 2. The apparatus of claim 1 wherein both ofsaid opposed rollers have their peripheral surfaces constituted of saidperipheral segments and said reciprocating means reciprocates thesegments of both said rollers.
 3. The apparatus of claim 2 wherein saidreciprocating means moves the segments of the respective rollers inopposite axial directions at substantially equal speeds.
 4. Theapparatus of claim 2 wherein said reciprocating means moves the segmentsof the respective rollers in opposite axial directions at unequal speedswhereby said strand is both twisted and laterally displaced.
 5. Theapparatus of claim 1 wherein said pair of opposed rollers is arrangedwith their axes extending at an oblique angle to the path of advance ofthe strand.
 6. The apparatus of claim 5 wherein each surface of asegment while in contact with said strand is moved axially at a pitchsubstantially twice said oblique angle.
 7. The apparatus of claim 1wherein said segmented roller includes a center core adapted to berotatively driven by said driving means, said core carrying a pluralityof axially extending tracks, each in mating engagement with one of saidperipheral segments, permitting individual axial reciprocation of saidsegments coincidental with bodily rotation thereof.
 8. The apparatus ofclaim 1 wherein each of said peripheral segments has a cam followerfixedly associated therewith and said reciprocating means comprises acam track engaging said cam followers.
 9. An apparatus for twisting orrolling an advancing textile strand generally about its axis whichcomprises a plurality of elongated elements each having a surface regionfor frictionally contacting the strand and arranged generallytransversely to the direction of advance of the strand, said elementsbeing mounted for individual movement to and fro along theirlongitudinal axes and for bodily movement at an angle to saidlongitudinal axes in a cyclical path, an opposed strand contactingsurface maintained in closely spaced relation to one locus on the pathof bodily movement of said elements and cooperating with at least oneelement at said locus to tightly engage the strand therebetween, meansfor driving said elements along said cyclical path, means for movingeach such element passing through said locus in a given longitudinaldirection in timed relation to the bodily movement of the elementthrough said cyclical path and subsequently along said cyclical pathmoving said elements in the opposite longitudinal direction, and meansfor advancing at least one textile strand to and withdrawing the strandfrom said locus along a generally rectilinear path, said element at saidlocus having its longitudinal axis extending generally across saidstrand path.